Apparatus for thermally fixing a non-silver free radical photosensitive composition

ABSTRACT

The heat fixing of non-silver free radical films is effected by blowing heated air directly at the film so that the air strikes the film approximately perpendicular to the film surface and a turbulence is created in the air adjacent to the film and the apparatus for effecting the same.

Unite States Low, Jr. et al.

"' atent H 1 APPARATUS FOR THE 1 i LY FIXING A NON-SILVER FREE RADICAL PHOTOSENSITIVE COMPOSITION Inventors: William H. Low, Jr., Shaker Heights; David R. Schaller, Chagrin Falls, both of Ohio Apr. 17, 1973 Primary ExaminerSamuel S. Matthews [73] Assignee: Horizons Incorporated, a Division of Assistant Examiner fiel Bram Horizons Research Incorpommd, Attorney-Lawrence I. Field 1 d C evelan Ohio TRACT 22 F] d: Oct. 20 1971 1 1e The heat fixing of non-silver free radical films is ef- [21] App]. No.2 190,720 fected by blowing heated air directly at the film so that the air strikes the film approximately perpendicular to the film surface and a turbulence is created in ((jil. "SS/c8331; the air adjacent to the film and the apparatus for f ti th [58 Field of Search 95/89 R, 89 o, 94 G; ec 6 Same 34/151, 219 2 Claims, 2 Drawing Figures |h.'"" 1m 6 i: l8 4 i i I I '4 I46 l 5 o t; l N I I I N 1 I I l 171 I i 44 L I 1 l of a 4o I I w 4 7T J Q --4. "J W f A I 1111111111111 I I1! APPARATUS FOR THERMALLY FIXING A NON- SILVER FREE RADICAL PHOTOSENSITIVE COMPOSITION This invention relates to an improvement in the thermal fixing of non-silver free radical photosensitive compositions of the type described in U.S. Pat. No. 3,042,515 and improvements thereon, e.g. those described in many of the patents listed in U.S. Pat. Nos. 3,493,376 and 3,510,304, for example.

The compositions in said patents include in many instances as a source of free radicals, an organic halogen compound such as iodoform or carbon tetrabromide or other organic compounds of similar structure along with a color forming compound, usually an organic amine which may be a dye or color former. During the thermal fixing steps these compounds tend to vaporize and leave the film,and heating accentuates this tendency.

In the past, fixing of such films has been accomplished by placing the film in a forced air oven, the film being disposed so that hot air has been caused to flow across the surface of the film. The flow of air swept away any vapor of organic halogen compound and other compounds evolved and leaves a photographically fixed film.

The laminar flow of air over the film surface is often uneven and results in uneven heating of the film. As a consequence the film may be completely fixed in one area and only partially fixed in an adjacent area. Furthermore, some of the thermal energy applied to fix the film may serve to develop or intensify the image in the film or to fog the film. In addition, the evolved compounds often are picked up by the film and produce false images.

In an effort to obviate these difficulties, the present invention is directed to an apparatus and process for applying a turbulent blanket of heated air to one side of a non-silver free radical photosensitive film to produce a more uniform fixing than has been achieved in the past.

The invention will be more clearly understood from the description which follows taken in conjunction with the drawings in which:

FIG. 1 is a view partly in section of one apparatus for practicing this invention; and,

FIG. 2 is a view in perspective, showing the manner in which the heated air makes contact with the photosensitive film being fixed.

One suitable apparatus shown in FIG. 1 comprises a housing 10, having an air inlet 12 and an air outlet 14. An air filter l6 guards the inlet and the air which passes through the apparatus and into plenum chamber 20 by a blower 18. The air is heated by a heater 22 positioned adjacent to the blower outlet 24 and soon fills the plenum chamber and raises the pressure therein so that the heated air seeks an exit. Such an exit is shown in the form of an open window at 26, from which the air moves toward the film surface F which the air strikes approximately perpendicular to the film surface, and is reflected back into the plenum chamber in which it creates a turbulence 30. Some air passes out through 2 the narrow space between the window of the plenum chamber and the film surface.

Air leaving the area is caused to traverse a charcoal filter 40 in which any pollutants are absorbed and then passes to the outlet passage 42 of the housing. A damper 44 may be used to selectlvely deflect the air to an exhaust port or to the blower inlet 46. It will be seen that the above described apparatus provides a turbulent zone of heated air adjacent to the surface of the film to be fixed and prevents redeposition of any of the compounds released by said film when it is heated.

Optionally the blower-heater may be two separate units, one of which blows (pushes) or sucks (pulls) air into the plenum chamber and the other of which heats the air.

Other optional features include a filter at the blower intake, a thermostat for checking the air temperature and activating the heater, and means to collect the air exiting from the region of the film, and to pass it through a filter or absorbent means so that the materials evolved from the photosensitive film do not escape to pollute the atmosphere and an outlet from which the air is vented to the atmosphere or recirculated to the blower-heater.

We claim:

1. An apparatus for thermally fixing a non-silver, free radical photosensitive film which comprises:

a housing provided with an inlet opening for admission of air into said housing and an outlet opening for discharging air from said housing;

means to support said film in said housing;

a plenum chamber in said housing, said plenum chamber being provided with an inlet opening and an outlet opening adjacent to said film support means;

a blower disposed in said housing and operatively connected to the inlet opening of said plenum chamber and the inlet opening of said housing whereby air drawn into said housing may be discharged into said plenum chamber;

means to heat said air before it leaves chamber;

said plenum chamber outlet means being positioned so as to direct said heated air perpendicularly against the surface of said film whereby a zone of turbulent air is provided adjacent to the surface of said film, said film is heated uniformly and substances evolved from said film when it is heated are not redeposited on the film;

deflecting means to selectively direct the air after it said plenum has left the surface of the film to exhaust through the air outlet in said housing or to recirculate through said blower; and

means located adjacent to said deflecting means to absorb the products evolved from said film when it is heated before the heated air is recirculated or exhausted.

2. The apparatus of claim 1 including means adjacent to the inlet to said plenum chamber to filter the air entering said chamber. 

1. An apparatus for thermally fixing a non-silver, free radical photosensitive film which comprises: a housing provided with an inlet opening for admission of air into said housing and an outlet opening for discharging air from said housing; means to support said film in said housing; a plenum chamber in said housing, said plenum chamber being provided with an inlet opening and an outlet opening adjacent to said film support means; a blower disposed in said housing and operatively connected to the inlet opening of said plenum chamber and the inlet opening of said housing whereby air drawn into said housing may be discharged into said plenum chamber; means to heat said air before it leaves said plenum chamber; said plenum chamber outlet means being positioned so as to direct said heated air perpendicularly against the surface of said film whereby a zone of turbulent air is provided adjacent to the surface of said film, said film is heated uniformly and substances evolved from said film when it is heated are not redeposited on the film; deflecting means to selectively direct the air after it has left the surface of the film to exhaust through the air outlet in said housing or to recirculate through said blower; and means located adjacent to said deflecting means to absorb the products evolved from said film when it is heated before the heated air is recirculated or exhausted.
 2. The apparatus of claim 1 including means adjacent to the inlet to said plenum chamber to filter the air entering said chamber. 